1. Field of the Invention
The present invention relates to an image forming apparatus, a method for controlling an image forming apparatus, and a recording medium on which a control program for an image forming apparatus is recorded. In particular, the present invention relates to an image forming apparatus forming an image based on an electrophotographic process, a method for controlling the image forming apparatus, and a recording medium on which a control program for the image forming apparatus is recorded.
2. Description of the Related Art
One type of the conventional control of an image forming apparatus is PPM (Pages Per Minute) control, under which the image processing rate is controlled to thereby reduce the productivity.
PPM control aims, for example, to allow an adequate time for cooling ejected sheets of paper, and thereby prevent “duplex tacking,” to reduce the frequency at which fixing heat is taken away by sheets of paper, and thereby prevent breakage of a fixing unit due to an increase in temperature of the edge of the fixing unit, and to allow an adequate time for cooling the inside of an image forming unit, and thereby prevent toner particles in the image forming unit from sticking together.
Generally employed methods for reducing the productivity under PPM control are:
1) a method by which the intervals between sheets of paper are increased by PPM control; and
2) a method by which printing is temporarily stopped (load is inactivated) and printing is resumed (load is activated) after standby for a predetermined time. Control 1) increases the intervals between sheets of paper, which prolongs the time for which the load is driven and accordingly increases power consumption. Therefore, in terms of power consumption, employment of Control 2) is considered more advantageous.
Control 2), however, still requires re-activation of the load after inactivation of the load and standby, which also prolongs the time for which the load is driven. Therefore, depending on what job is performed, above Control 1) may be able to reduce power consumption to a greater extent. Namely, although above Control 2) has conventionally been employed for reducing power consumption, there has been a problem that Control 2) may not actually be optimum control for reduction of power consumption.